chore(workspace): install all 4 bundled hooks + model default update

- Installed hooks: boot-md, session-memory, command-logger, bootstrap-extra-files
- Updated default model to litellm/copilot-claude-sonnet-4.6
- Added memory/startup-health.json + boot-last-run.json from boot check
- Added memory/startup-health.md warning log
- Captured new session memory files (2026-03-04/05)
- Minor MEMORY.md + USER.md: added git preference line

memory/boot-last-run.json

@@ -0,0 +1 @@
+{"last_run_utc": "2026-03-05T04:28:00Z", "status": "warn"}